September will be a big month for the Simms siblings, who grew up in Clearwater. Automatic Loveletter is embarking on a cross-country tour with Mest and Quietdrive, while Win Win Winter is gearing up for their first trip up the East Coast. But first, on Friday, the two bands will share a stage for one night only at St. Pete's State Theatre.

To mark the occasion, tbt* called Juliet Simms, 22, to chat about her relationship with Tommy and the speedy rise of her band, whose debut full-length LP will come out in May. (For more on Win Win Winter, see our concert picks on Page 26.)

When did Automatic Loveletter and Win Win Winter last play together?

Oh, wow. Gosh. A year and a half ago? It's been awhile.

Did you and Tommy grow up in a musical family?

My grandpa, my aunt, my uncle — everybody can pretty much play an instrument. My grandpa is a jazz pianist, and my aunt is a professional violinist, and my uncle is a bassist. My dad plays harmonica. My mom can sing. Growing up, when we'd have family holidays ... it was always a big jamfest.

When did you guys join the jam?

Ever since I was 3 years old, I was learning Disney songs. So I was always in there singing along. But as far as instruments go, I was like 8 or 9, and Tommy was 11.

Did you write songs together?

We have. Our styles are so different — he's got that really cool indie-rock thing going on, and I'm more mainstream, you could say. But when we do get together, we've made some pretty cool s---.

Are you competitive with each other?

We're not ... anymore. We definitely were when we were younger. If one was getting more attention, the other one would get jealous. We're both "frontpeople" too, so you're dealing with the spotlight and we're brother and sister. It's like double disaster. (laughs)

Automatic Loveletter did the Warped Tour this year. How bummed were you that you didn't get to play St. Pete?

We played on it for four and a half, five weeks, but all those dates were after St. Pete. It was definitely a bummer.

What were some of the highlight?

If you can survive Warped Tour, you are gnarly. (laughs) And we made friends with so many bands! I got to hang out with Tom DeLonge ... so that was pretty cool. Katy Perry. Story of the Year came to our set a bunch of times. Even Angels and Airwaves came to our set. The singer of All That Remains must have watched our set for two weeks straight. He must have been in love with us.

What did you learn that'll help you?

I learned that being nice to people goes a long way. To take the time to learn everybody's name, and say hi to them in the morning, and tell them thank you — that makes them want to help you back. ... We brought (Warped Tour founder) Kevin Lyman all our merch one day, and I bought him two really good bottles of wine, and the next thing we know, we're being bumped up to one of the second-to-main stages.

What do you do when you come back to Tampa Bay, besides just rest?

I write a lot. I catch up on my movies. I go to my favorite restaurants, like this Japanese restaurant called Joto. I go to the beach at night with friends and bring our guitars. Basically, when I come home, I'm not here for that long, so it's like a tiny little vacation.

Automatic Loveletter

The band plays with Win Win Winter, Tides of Man, Tres Bien, Mumpsy and Lavin at the State Theatre, 687 Central Ave., St. Petersburg. Doors open at 7 p.m. Show starts at 8 p.m. Tickets are $5-$8. (727) 895-3045, statetheatreconcerts.com. You can also catch Automatic Loveletter at 8 p.m. Sept. 11 at Bourbon Street in New Port Richey; get details at clubbourbonstreet.com.